The ramblings of a geek

Testing client web applications and websites often means migrating them temporarily to my development network for testing purposes. This means changing email server settings to ensure no emails escape from captivity, which would be embarrassing.

Occasionally I have issues with my internal email configuration and need to do a quick test to see if my internal email server is receiving emails from my website development servers. This can easily be achieved using the command line and telnet.

First off we need to esablish a connection to the email server, so telnet into your SMTP server from the command line like so:

telnet [ip-address] 25

Where ip address is your email server e.g “telnet 10.10.10.1 25″. The 25 signifies your SMTP port, 25 is the default.

We now need to check if the SMTP server is alive. So we can use:

EHLO

What you get back depends on your SMTP server, OS etc. but you should get an OK message at least.

Now we want to send a test message to see if our SMTP server is receving email okay from our local network. To do this we need to tell it the email sender, email recipient and of course the message. The message  is in two parts – subject and body (although you dont have to fill in the subject as it is not mandatory). We do this using:-

mail from:email@emailsender.com

rcpt to:email@yourdomain.com

To send the actual message we need to type the command:

Data

Followed by a carriage return (enter).

To enter the subject we use:

Subject: Subject goes here

Then press enter TWO times.

You can now start typing the body of your email message. To finish the email body text input, enter a carriage return (enter) and then tpye a period (.) followed by carriage reutrn (enter) again.

Finally enter:

quit

To exit the telnet program.

You should get an OK or message queued for delivery message back saying that the SMTP server has accepted the message. If not you have entered something wrong, or the email server doesnt like the message (for example an email relay config issue blocking you sending from your IP address).

Hope that is of help.

Although it has been out for a while, I recently came across Googles 2-step verification security system. For those of you not in the know, you can find out more here:-

Google 2-step Verification Overview and Video

If you are security conscious or paranoid (or maybe even both) this is a good option to beef up your PC/device security for your Google apps, especially if you have a Android phone to act as the authenticator (the Google android apps is called Google Authenticator and can be downloaded from Google Marketplace on your android phone (its also available for iPhone too).

With this installed and configured you have to enter your password and the authentication code from displayed on your Android Phone to succesfully log-into a Google resource. So not only will a hacker have to know your password, but also your authentication code (which changes every few seconds).

This drove me crazy. I use keepass for almost everything, and now and again it would stop working.

Finally figured out it only happened when I had VMware vSphere console open, obviosuly they conflict in some way.

Solution is to download the keepass plugin RDCAutoType from here - http://rdc-keepass-plugin.appspot.com/

This also has the bonus of working with Remote Desktop Connections (RDP).

I’ve started using Bitnami images for my test/dev system. They provide a quick way to get web apps up and running, however as they are optimised/minimal builds sometimes they need tweaking.

I’m based in the UK and the standard keyboard mapping is set for US. To reset for a different country/keyboard type use:-

sudo dpkg-reconfigure console-setup